than twice the amount of wood and 160 times 

 more sediment than does the Eastern Forest 

 ecogroup. Also, the Western Forest ecogroup 

 in the National Forest System produces about 

 three times more water than the Eastern For- 

 est ecogroup in the National Forest System. 

 About 40 percent of this water yield from the 

 Western Forest comes from the Fir-spruce 

 ecosystem although it accounts for only 20 

 percent of the acreage in National Forest Sys- 

 tem forest lands. The Alpine ecosystem is an- 

 other major water source, contributing 15 per- 

 cent of the water yield from the National 

 Forest System lands. 



Qualitative outputs for the forest-range lands 

 were principally rated fair to good for all eco- 

 groups (fig. 22). One major exception above 

 the norm was the lesser soil stability in the 

 Western Range, exemplified by high sediment 

 yields. 



SUMMARY 



This study estimated that 1.2 billion acres, 

 or 63 percent, of the total land area in the 

 48 conterminous United States is in forest- 

 range environment. It was estimated that 835 

 million acres, or 69 percent, was grazed by 

 livestock in 1970. 



The 11 western States dominated, both in 

 terms of total area and proportion of land in 

 forest-range. However, the Great Plains eco- 

 group had the largest percentage of forest- 



range land grazed, 94 percent, followed closely 

 by the Western Range ecogroup, with 88 per- 

 cent. 



About three-fourths of the grazed land was 

 managed for livestock at extensive levels. Max- 

 imizing for livestock production occurred on 

 about 50 million acres and was concentrated 

 in the Prairie, Plains grasslands, and Mountain 

 grasslands ecosystems. Exploitative grazing 

 was occurring on 72 million acres of the East- 

 ern Forest ecosystems. 



It was estimated that the Nation's forest- 

 range resource produced 213 million animal 

 unit months in 1970. While AUM output was 

 spread nationwide, 70 percent was furnished 

 in the Great Plains and Western Range eco- 

 groups. A majority of the AUM production was 

 on non-Federal lands. 



Forest-range lands were also highly produc- 

 tive for a wide variety of other products. It 

 was estimated that the average acre of forest- 

 range produced 0.4 ton of herbage and browse 

 and 0.65 acre foot of water yearly. It was also 

 estimated that annual net wood growth on the 

 forest-range land was 20.5 billion cubic feet. 

 Qualitative outputs were principally rated fair 

 to good for all ecosystems. 



REFERENCES 



Water Resources Council 



1968. The Nation's Water Resources. Washington, 

 D.C. U.S. Government Printing Office 



37 



